PZS Nanotubes Research Articles

Fabrication of Bimetallic Cu-Ag Nanoparticle-Decorated Poly(cyclotriphosphazene-co-4,4'-sulfonyldiphenol) and Its Enhanced Catalytic Activity for the Reduction of 4-Nitrophenol.

We reported a study on the preparation of bimetallic Ag–Cu nanoparticles (NPs) impregnated on PZS poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) nanotubes via a facile and efficient reduction method. Herein, PZS nanotubes consisting of enriched hydroxyl groups are fabricated through an in situ template method, and then, fluctuating the amount ratios of Cu and Ag precursors, bimetallic NPs can be fabricated on readily prepared PZS nanotubes using NaBH4 as a reductant, which results in a series of bimetallic catalysts having tunable catalytic activity. The characterization investigations of scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy results show that Ag–Cu bimetallic NPs are well-dispersed, ultrasmall in size, and well-anchored on the surface of PZS nanotubes. In addition, to examine the catalytic activity and reusability of these nanocomposites, reduction of 4-nitrophenol to 4-aminophenol is utilized as a prototype reaction. The optimized Ag–Cu NPs with a copper ratio of 0.3% are well-stabilized by the organic–inorganic poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) nanotubes. The obtained results show that bimetallic NPs have remarkably higher catalytic ability than that of their monometallic counterparts with maximum catalytic activity. These results are even better than those of noble metal-based bimetallic catalysts and pave the avenue to utilize the polyphosphazene polymer as a substrate material for highly effective bimetallic catalysts.

Synthesis of a functionalised phosphazene‐containing nanotube/epoxy nanocomposite with enhanced flame retardancy

Poly(cyclotriphosphazene-co-4,4′-sulphonyldiphenol) nanotubes (PZS) were synthesised via an in situ template method under mild conditions and applied on epoxy resin (EP) as a novel flame retardant. The PZS nanotubes were characterised by SEM, TEM, EDS and element mapping and the flammability was investigated by microscale combustion calorimeter and limited oxygen index (LOI) tests. The results showed a significant improvement of the carbonisation ability and flame retardancy of The PZS/EP nanocomposites. Under merely 3% of addition of PZS nanotubes, the LOI value was increased to 30.1 from 26.6, the peak of heat release rate was reduced to 335 W/g, about 40% lower than that of neat EP. The great improvement of flame retardancy can be ascribed to the formation of graphene-like structure during combustion of PZS/EP nanocomposites.

Removal of Rhodamine B, a Cationic Dye From Aqueous Solution Using Poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) Nanotubes

Poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) nanotubes were evaluated as an efficient adsorbent for the removal of Rhodamine B (RhB), a cationic dye from aqueous solution. The as-synthesized adsorbent (PZS nanotubes) were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) and N2 adsorption/desorption isotherms. The factors influencing the adsorption efficiency and capacity had been systematically studied. Results showed that the adsorption was highly dependent on temperature, initial RhB concentration and adsorbent dose. Effects of initial solution pH indicate that the adsorption can proceed in both basic and acidic environment. The equilibrium absorption capacity at 25°C can reach up to 35.58 mg/g within 60 min implying the adsorption procedure was highly rapid. The kinetic data was better described by the pseudo-second-order model with the correlation coefficient (R2 = 0.9981), and the adsorption process followed Weber's intraparticle model, indicating the adsorption process could be divided into two stages. Results also showed that the adsorption equilibrium obeyed the Langmuir isotherm, and the value of equilibrium parameter RL suggested that the PZS nanotubes were an efficient adsorbent for the removal of RhB from aqueous solution.

Preparation of UV-curable functionalized phosphazene-containing nanotube/polyurethane acrylate nanocomposite coatings with enhanced thermal and mechanical properties

Poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) nanotubes with active hydroxyl groups were fabricated via an in situ template method under mild conditions, and then modified by acryloyl chloride to obtain the acryloyl-group functionalized PZS (f-PZS) nanotubes.

Adsorption of methylene blue onto poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) nanotubes: Kinetics, isotherm and thermodynamics analysis

Poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) nanotubes, an excellent adsorbent, were successfully synthesized by an in situ template method and used for the removal of methylene blue (MB) from aqueous solution. The morphology and structures of as-synthesized PZS nanotubes were characterized by scanning electron microscopy, transmission electron microscope, Fourier transform infrared spectroscopy and N2 adsorption/desorption isotherms. The effects of temperature, concentration, pH and contact time on MB adsorption were studied. It was favorable for adsorption under the condition of basic and high temperature. The pseudo-first-order, pseudo-second-order and intraparticle diffusion models were used to fit adsorption data in the kinetic studies. And results showed that the adsorption kinetics were more accurately described by the pseudo-second-order model. The equilibrium isotherms were conducted using Freundlich and Langmuir models. It has been demonstrated that the better agreement was Langmuir isotherm with correlation coefficient of 0.9933, equilibrium absorption capacity of 69.16mg/g and the corresponding contact time of 15min. Thermodynamic analyses showed that MB adsorption onto the PZS nanotubes was endothermic and spontaneous and it was also a physisorption process.

Silver nanoparticles-decorated polyphosphazene nanotubes: synthesis and applications

Herein, we report the preparation of poly (cyclotriphosphazene-co-4,4'-sulfonyldiphenol) (PZS) nanotubes decorated with Ag nanoparticles (NPs). The PZS nanotubes have been synthesized firstly via an in situ template approach, and then Ag nanoparticles were prepared via in situ reduction of AgNO3 with NaBH4 as the reductant, supported on the surface of the PZS nanotubes. The as-obtained PZS nanotubes and PZS@Ag NPs composites were characterized by means of Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) equipped with energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), thermogravimetric analysis (TGA), and UV-vis spectroscopy. Characterization results showed that Ag NPs with good dispersibility were well anchored onto the surface of the PZS nanotubes with superior thermal stability. In addition, the catalytic activities and reusability of these composites were investigated by employing the reduction of 4-nitrophenol (4-NP) into 4-aminophenol (4-AP) by NaBH4 as a model reaction.

Controlled fabrication of noble metal nanoparticles loaded on the surfaces of cyclotriphosphazene-containing polymer nanotubes

We report on the fabrication of noble metal nanoparticles loaded on the surfaces of cross-linked poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) nanotubes of high stability. PZS nanotubes were first synthesized by precipitation polymerization between hexachlorocyclotriphosphazene and 4,4′-sulfonyldiphenol based on in situ template mechanism. Then the PZS nanotubes were directly used as scafford to load metal Au, Ag, and Pd nanoparticles, respectively, through cation complexation followed by gentle reduction. The structure and morphology of the metal/PZS nanocomposites were determined by means of Fourier transform infrared spectra, energy dispersive X-ray spectroscopy, elemental analysis, X-ray diffraction, scanning electron microscope, transmission electron microscope, and thermogravimetric analysis (TGA). Results showed that the metal/PZS nanocomposites possessed 460 °C of initial thermal decomposition temperature under air atmosphere and the loading amount of metal nanoparticles on the PZS nanotube surfaces could be controlled easily. As-fabricated metal/PZS nanocomposites are expected to have potential applications in catalysis.

Enhanced electrochemical properties of polyethylene oxide-based composite solid polymer electrolytes with porous inorganic–organic hybrid polyphosphazene nanotubes as fillers

Solid composite polymer electrolytes consisting of polyethylene oxide (PEO), LiClO4, and porous inorganic–organic hybrid poly (cyclotriphosphazene-co-4, 4′-sulfonyldiphenol) (PZS) nanotubes were prepared using the solvent casting method. Differential scanning calorimetry and scanning electron microscopy were used to determine the characteristics of the composite polymer electrolytes. The ionic conductivity, lithium ion transference number, and electrochemical stability window can be enhanced after the addition of PZS nanotubes. The electrochemical impedance showed that the conductivity was improved significantly. Maximum ionic conductivity values of 1.5 × 10−5 S cm−1 at ambient temperature and 7.8 × 10−4 S cm−1 at 80 °C were obtained with 10 wt.% content of PZS nanotubes, and the lithium ion transference number was 0.35. The good electrochemical properties of the solid-state composite polymer electrolytes suggested that the porous inorganic–organic hybrid polyphosphazene nanotubes had a promising use as fillers in SPEs and the PEO10–LiClO4–PZS nanotube solid composite polymer electrolyte might be used as a candidate material for lithium polymer batteries.

Preparation and electrochemical behaviors of composite solid polymer electrolytes based on polyethylene oxide with active inorganic–organic hybrid polyphosphazene nanotubes as fillers

Inorganic–organic hybrid porous poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) nanotubes with active hydroxyl groups are incorporated in polyethylene oxide (PEO), using LiClO4 as doping salts, to form a novel composite polymer electrolyte (CPE). The composite solid polymer electrolytes are characterized using differential scanning calorimetry (DSC), atomic force microscopy (AFM), scanning electron microscopy (SEM) and electrical impedance spectroscopy. The SEM photographs indicate that the electrolytes are miscible and homogeneous. Incorporation of active PZS nanotubes in PEO–LiClO4 polymer electrolytes facilitates salt dissociation and enhances ionic conductivity. Maximum ionic conductivity values of 4.5 × 10−5 S cm−1 at ambient temperature and 1.56 × 10−3 S cm−1 at 80 °C are obtained when the content of active PZS nanotubes is 10 wt% and the lithium ion transference number is 0.39. The experiment results show that the inorganic–organic hybrid polyphosphazene nanotubes with active hydroxyl groups can enhance the ionic conductivity and increase the lithium ion transference number of PEO-based electrolytes more effectively comparing with traditional ceramic fillers such as SiO2.

A facile strategy for the functionalization of poly[cyclotriphosphazene‐co‐(4,4′‐sulfonyldiphenol)] materials

AbstractRecently, a new type of phosphazene‐containing material, poly[cyclotriphosphazene‐co‐(4,4′‐sulfonyldiphenol)] (PZS), was successfully prepared. PZS materials including PZS nanotubes, PZS nanofibers and PZS microspheres show excellent thermal stability, biocompatibility and biodegradability. Moreover, PZS‐containing materials such as silver nanowire/PZS, carbon nanotube/PZS and Fe3O4/PZS nanotubes have also been prepared. Therefore, we explored a specific method for the functionalization of these PZS and PZS‐containing materials to expand their scope of application. As a model of various PZS and PZS‐containing materials, PZS microspheres (PZSMs) were functionalized via surface‐initiated atom transfer radical polymerization (ATRP). Polymerization of styrene occurred at surface sites covalently derivatized with ATRP initiators to form PZSM–polystyrene. The number‐average molecular weight (Mn) of grafted polymer chains could be well controlled. Furthermore, PZSM–polystyrene was still active for further block copolymerization of methyl methacrylate. Both styrene‐ and acrylate‐type monomers could be directly polymerized or block copolymerized from the surface of PZS and PZS‐containing materials using surface‐initiated ATRP. Mn of grafted polymer chains could be well controlled. This facile strategy could pave the way for a wider range of applications of these materials. Copyright © 2010 Society of Chemical Industry

Effect of surface modified porous inorganic-organic hybrid polyphosphazene nanotubes on the properties of polyethylene oxide based solid polymer electrolytes

2-(2-methyloxyethoxy)ethanol modified poly (cyclotriphosphazene-co-4,4′-sufonyldiphenol) (PZS) nanotubes were synthesized and solid composite polymer electrolytes based on the surface modified polyphosphazene nanotubes added to PEO/LiClO 4 model system were prepared. Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM) were used to investigate the characteristics of the composite polymer electrolytes (CPE). The ionic conductivity, lithium ion transference number and electrochemical stability window can be enhanced after the addition of surface modified PZS nanotubes. The electrochemical investigation shows that the solid composite polymer electrolytes incorporated with PZS nanotubes have higher ionic conductivity and lithium ion transference number than the filler SiO 2. Maximum ionic conductivity values of 4.95 × 10 −5 S cm −1 at ambient temperature and 1.64 × 10 −3 S cm −1 at 80 °C with 10 wt % content of surface modified PZS nanotubes were obtained and the lithium ion transference number was 0.41. The good chemical properties of the solid state composite polymer electrolytes suggested that the inorganic-organic hybrid polyphosphazene nanotubes had a promising use as fillers in solid composite polymer electrolytes and the PEO 10-LiClO 4-PZS nanotubes solid composite polymer electrolyte can be used as a candidate material for lithium polymer batteries.

The controlled preparation of cross-linked polyphosphazene nanotubes of high stability via a sacrificial template route

We report on the controlled preparation of cross-linked poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) nanotubes using Ag nanowires as sacrificial templates. The as-prepared PZS nanotubes have a good chemical stability in concentrated nitric acid and an initial 475 °C thermal decomposition temperature in air.

A facile route to synthesis of magnetic phosphazene-containing polymer nanotubes at room temperature

Magnetic phosphazene-containing polymer nanotubes were successfully prepared via a facile approach at room temperature by ultrasonic irradiation. The structure and morphology were characterized by XRD, EDX, SEM and TEM. The characterization results show that the phosphazene-containing polymer nanotubes are 50–80 nm in outer diameter and 5–10 nm in inner diameter; the Fe3O4nanoparticles loaded on the outer surface are 5–10 nm in diameter. The coordination behaviour between magnetic nanoparticles and PZS nanotubes was investigated by IR. TG curves show that the magnetic nanotubes have good thermostable properties and high magnetism content. The magnetic properties of the Fe3O4/polymer nanotubes were also investigated. The results show that the magnetic nanotubes have high magnetization saturation value and exhibit good superparamagnetic properties.

Novel synthesis of magnetic poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) nanotubes with magnetic phases embedded in the walls

Magnetic poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) nanotubes with magnetic phases embedded in the walls were synthesized by ultrasonic irradiation via an in situ template approach. The structure and morphology of the magnetic PZS nanotubes were determined by FT-IR, XRD, FE-SEM, HR-TEM and EDX spectroscopies. The characterization results show that the magnetic PZS nanotubes are 50–100 nm in outer diameter and 5–10 nm in inner diameter; the Fe3O4nanoparticles with diameter of 5–10 nm are embedded in the walls of the nanotubes. The morphology of the magnetic PZS nanotubes is greatly influenced by the content of Fe3O4nanoparticles. A possible formation mechanism of the magnetic PZS nanotubes is proposed. The TGA results and the magnetic measurements show that the magnetic PZS nanotubes have good thermal stability and superparamagnetic properties.